Film forming apparatus



. June 6, 1939. E, c JEWETT 2,161,356

FILM FORMING APPARATUS Filed July 27, 1938 fora/d CJeA/ezz l N VENTOR 25 29 f AT T RNEYS latented June 6 1939 PATENT OFFICE FILM FORMING APPARATUS Earold C. Jewett, Rochester, N. Y., assignor to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application July 27, 1938, Serial No. 221,644

10 Claims.

The present invention relates to the manufacture of film base from cellulosic dope containing volatile solvents, and more particularly to an improved form of casing through which the cur- 5 ing air is passed to remove the solvent from the deposited dope.

7 One object of the invention is the provision of a curing casing which may be readily and easily adjusted to control the velocity of the air stream therethrough.

Another object of the invention is the provisionof an adjustable air curing casing, the shape of which may be varied to suit the type 15 of dope being deposited on the coating wheel.

vision of an air curing casing formed of a plurality of sections each of which may be separately and independently adjusted to control the air velocity at different points around the periphery of the casting wheel, said adjustments depending on the curing rate and other characteristics of the particular type of dope involved.

A still further object'of the invention is the provision of a casing of the type described which is simple in construction, comprises few parts of rugged constructiomis easy to assemble and adjust, and is highly effective in use.

To these and other ends, the invention resides in certain improvements and combinations of parts all as willbe hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawing:

Fig. 1 is a vertical sectional view through a coating wheel of the usual construction, showing the relationthereto of an adjustable air curing I, casing constructed in accordance with the preferred embodiment of the invention;

- Fig. 2 is a perspective view of a portion of the machine illustrated in Fig. 1, but on a larger scale than the latter, showing the relation of the parts of the adjustable air casing, and the means for supporting and adjusting the various sections or leaves of the casing; and 4 Fig. 3 is a horizontal sectional view taken substantially on the line 33 of Fig. 1, showing the relation of the adjustable air casing to the coating wheel.

Similar reference numerals throughout the 5 various views indicate the same parts.

.In the manufacture of film base, a suitable dope III, of cellulosic or other suitable material containing volatile solvents, is. supplied to a dope hopper II, of any well-known construction, from which it flows in a thin ribbon onto a coating A further object of the invention is the proter is finally slipped off the drum in a form of a continuous sheet or web I5, all as well known to those in the art.

In the type of machine generally used, a metal casing I6 is provided to direct a stream of heated curing air along the surface of the drum I2. The heated air is supplied to the casing I6 through the inlet I1 and is discharged through the outlet I8. This air has the dual purpose of supplying heat to remove the solvent or solvents from the dope solution, and of supplying a vehicle by means of which the vapor may be removed from the machine. In the region near the point at which the dope I0 is deposited on the drum l2, the space I9 between the casing I6 and the surface 20 of the wheel I2 must be relatively large, as the uncured dope cannot come in contact with a stream of air moving at high velocity without causing ripples or other irregularities in the finished sheet or web I5. The major portion of the casing I6 is, however, spaced a substantially uniform distance from the wheel surface 29, as clearly shown in Fig. 1.

In the present embodiment, the casing I6 comprises a pair of end frames 22, only one of which is shown, arranged at opposite ends of the drum I2 and projecting radially above the wheel surface 20, as clearly shown in Figs. 2 and 3. These end frames 22 are connected by a plate 23 which rests on the top of the end frame 22 and cooperates with the latter to provide a casing I6, as is apparent from an inspection of Figs. 2 and 3. These end frames 22 and the plate 23 may be broadly considered as an outer casing.

Obviously, the velocity of a curing air stream will be substantially constant throughout the uniformly spaced portion of the casing I6. However, as different types of dope have different curing rates and characteristics, the maximum air velocity which could be maintained at any point along the wheel I2 will vary with the type of dope and other coating factors. Nevertheless it is desirable to maintain this velocity at as high a value as possible because the rate of heat transferring increases as the velocity increases. Therefore, in order to accurately adjust the velocity of the curing air to the proper value for the dope being used, the present invention provides a secondary air casing, the shape of which may be readily and easily varied to secure the required air velocity at different points along the curing path of the web I5.

This adjustable secondary air casing, generally indicated by the numeral 25, is positioned between the outer casing l6 and the drum" surface 20, as clearly illustrated in Fig. 1. In the preferred embodiment, this inner casing 25 is made up of a series of interlocking or overlapping arcuate shaped leaves 26, as best shown in Fig. 2. A rod 21 extends across the outer surface 28 of each leaf 28, adjacent one end 29 thereof, and is secured by hinged clamps 35, only one of which is shown, to the leaf surface 28. Rivets 3|, or other suitable fastening means; fixedly secure the hinged clamps 30 to the leaf surface 28, as clearly shown in Fig. 2. The opposite ends of each rod 21 are suitably secured to the lower ends of ad moving the opposite pair of rods 35 along the grooves 36; Set screws 59 in the brackets 38 serve to maintain the rods 35 in adjusted position. It is thus apparent from an inspection of Fig. 2 that each pair of rods 35 not only provide a support for one end of a leaf 26, but also afford a means for moving the leaf radially of the drum I2. Such movement of the leaves is utilized' to vary the spacing between the leaves and the surface 20 of the drum so as to control the air velocity at various points along the drum surface to effectively cure the type of dope deposited on the drum. The other end 42 of each leaf 26 overlaps the end 23 of the adjacent leaf, and is supported thereby, as clearly. shown in Fig. 2. Thus each leaf 26 has one end 29 thereof supported by its rods 35 while the other end 42 rests on and is supported by the end 29 of the adjoining leaf, as clearly shown in Fig. 2. By means of this arrangement, any adjustment of the rods 35 of any leaf serves to move the end 29 of that leaf and also the overlapping end 42 of the adjacent leaf.

The overlapping ends 29 and 42 of the adjoining leaves are arranged in a manner clearly shown in Fig. 2, the direction of air flow being indicated by the arrow. The end 42 of each leaf 26 is resiliently maintained in contact with the radially controlled end 29 of the adjacent leaf by means of a spring clip 45 one end 45 of which is fixedly secured to the surface 23 adjacent the rod 21, while the free end 4'! thereof engages the exposed face of the end 42, as best shown in Fig. 2. This spring clip thus holds the overlapping ends 42 and 29 incontact to afford a substantially air-tight joint, yet allows the end E2 to slide along the surface 28 of the adjacent leaf to compensate for changing peripheral distances as adjustment of the leaves is being made.

This adjustable inner casing 25 provides an air chamber 55 through which a stream of ouring air may pass, as shown in Fig. 1. In order to be sure that substantially all the air supplied through the inlet I i will pass along the chamber 55, suitable flexible sealing strips 5| of canvas, or other suitable material, are positioned between the inner and outer casings in the position shown in Fig. 1. This flexible or adjustable inner casing construction permits the varying of the distance between the casing and the drum. surface 28 so as to maintain the maximum per missible velocity at any point along the wheel surface. Thus the best curing velocity for the particular dope may be secured at all points in the curing path.

If the newly deposited dope is subjected to high velocity air, ripples and other irregularities may be formed in the finished web l5, as stated above. In order to prevent this ripple formation, the'discharge end of the chamber 50 is preferably flared out, asshown at 52, Fig. 1, to quickly reduce the air curing velocity to the proper value required for the particular dope used. To secure this adjustment, the end leaf 55 of the casing 25 is preferably made somewhat flexible so that the free end 56 thereof may be radially moved sufficiently to properly control the discharge air velocity. If desired, the end leaf 55 may be secured to the adjoining leaf by a hinge rather than by the clips 45. o

The free end 56 of the leaf 55 is pivotally connected to a lever 51 pivoted at 58 to one end of a lever 59 the other end of which is connected to a shaft 60. A gear portion BI is mounted on the shaft Gil and meshes with a worm 62 carried by a rod 53 which extends horizontally through and exteriorly of the casing I6, as clearly shown in Fig. 1. Thus by turning the rod 63, the worm 62 is also turned to move the gear 6| and shaft 60 to cause the levers 5? and 59 to move relative to each other. This relative movement will adjust the end 56 radially toward'or away from the drum [2 to control the size of the discharge opening 52 of the chamber 50 as is apparent from an inspection of Fig. 1. Such an arrangement assures that the velocity of the air at the discharge end of the chamber 55' will be sufficiently reduced to prevent the formation of rippics on the newly deposited dope.

It is thus apparent from the above description In addi- While one embodiment of the invention has been disclosed, it is to be understood that the inventive idea may be carried out in a number of ways. This application is, therefore, not to be limited to the precise details described, but is intended to cover all variations and modifica tions thereof falling within the spirit of the invention or the scope of the appended claims.

I claim:' I

1. In an apparatus for forming a film from a dope, the combination with a drum on which the dope is deposited to form a continuous strip of film, of a multi-section casing surrounding a portion of said drum and cooperating therewith to provide a chamber through which a stream of air may be passed to cure the dope deposited on said drum, and means for separately adjusting each of said sections relative to said drum.

2. In an apparatus for forming a film from a dope, the combination with a drum on which the dope is deposited to form a continuous strip of film, of a multi-section casing surrounding a portion of said drum and cooperating therewith to provide a chamber through which a stream of air may be passed to cure the dope deposited on said drum, resilient means for maintaining said sections in alignment, and means for independently adjusting each of said sections relative to said drum to control the velocity of said stream.

3. In an apparatus for forming a film from a dope, the combination with a drum on which the dope is deposited to form a continuous strip of film, of a multi-section casing surrounding the major portion of said drum and cooperating therewith to form a chamber through which a stream of air may be passed to cure the dope deposited on-said drum, spring clips carried by said sections to maintain the latter in alignment to provide a continuous and substantially airtight chamber, and means for independently adjusting said sections toward and away from said drum to vary the shape of said chamber to control the'velocity of said stream.

4. In an apparatus for forming a film from a dope, the combination with a drum on which the dope is deposited to form a continuous strip of film, of a casing surrounding said drum and cooperating therewith to provide a chamber through which a stream of air may be passed to cure the dope deposited on said drum, said casing comprising a series of overlapping leaves, resilient means for maintaining adjacent portions of said leaves in engagement to provide a substantially air-tight chamber, and means for separately adjusting said leaves radially of said drum to control the velocity of said stream.

5. In an apparatus for forming a film from a V dope, the combination with a drum on which the dope is deposited to form a continuous strip of I film, of a casing surrounding said drum and coopcrating therewith to provide a chamber through which a stream of air may be passed to cure the dope deposited on said drum, said casing comprising a series of overlapping leaves, means for independently adjusting one end of each leaf radially of said drum to control the velocity of said stream, and means for maintaining the other end of an adjoining leaf in contact with said one end.

6. In an apparatus for forming a film from a dope, the combination with a drum on which the dope is deposited to form a continuous strip of film, of a casing surrounding said drum and cooperating therewith to provide a chamber through which a stream of air may be passed to cure the dope deposited on said drum, said casing comprising a series of overlapping leaves,

means for independently adjusting one end of each leaf radially ofsaid drum to control the velocity of said stream, the other end of each leaf overlapping the adjustable end of an adjoining leaf to provide a continuous air chamber, and resilient means carried by said one end and engaging the other end of an adjoining leaf to maintain said ends in contact.

7. In an apparatus for forming a film from a dope, the combination with a drum on which the dope is deposited to form a continuous strip of film, end frames positioned at opposite ends of said drum and projecting radially above the surface thereof, of a multi-section casing surrounding said drum and cooperating therewith toprovide a chamber through which a stream of air may be passed to cure the dope deposited to form an outer casing surrounding the major portion of said drum, of a secondary casing positioned between the outer casing and said drum and cooperating with the latter to provide a chamber through which a stream of air may be passed to cure the dope deposited on said drum, said secondary casing comprising a series of overlapping leaves, separate means carried by said frames for independently supporting one end of each leaf and the overlapping end of an adjoining leaf, resilient means for maintaining the overlapping portions of said leaves in contact, and means for moving said supporting means to adjust said leaves radially of said drum to control the velocity of said stream through said chamber.

9. In an apparatus for forming a film from a dope, the combination with a drum on which the dope is deposited to form a continuous strip of film, an outer casing surrounding the major portion of said drum, of an inner casing positioned between said outer casing and said drum and cooperating with the latter to form an air chamber through which a stream of air may be passed to cure the dope deposited on said drum, said inner casing comprising a series of separate and independent leaves the ends of which are arranged in overlapping relation to provide a continuous substantially air-tight chamber, said leaves extending across the face of said drum and in spaced relation thereto, means mounted on said outer casing and operatively connected to each of said leaves to separately support one end of each leaf, the other end of each leaf being supported by the said one end of an adjoining leaf, spring clips carried by each leaf adjacent said supporting means and engaging said other end to maintain the overlapping portions of said leaves in contact, and means for moving said supporting means radially of said drums to adjust said leaves relative thereto to control the air velocity in said chamber.

10. In an apparatus for forming a film from a dope, the combination with a drum on which the dope is deposited to form a continuous strip of film, an outer casing surrounding the major portion of said drum, of an inner casing positioned between said outer casing and said drum and cooperating with the latter to form an air chamber through which a stream of air may be passed to cure the dope deposited on said drum, said inner casing comprising a series of separate and independent arcuate leaves, the ends of which are arranged in overlapping relation, said leaves extending across the face of said drum and in spaced relation thereto, pairs of rods slidably mounted on opposite sides of said outer casing, each pair of rods having the lower ends operatively connected to one of said leaves to support the latter adjacent one end thereof, the opposite end of each leaf being supported by the one end of an adjoining leaf, spring clips mounted on each of said leaves adjacent the one end thereof and having a portion arranged to engage the other end of an adjoining leaf to maintain the overlapping leaf portions in contact, and means for moving said pairs of rods to separately adjust said leaves radially of said drum to vary the size of said chamber to control the velocity of said stream.

- EAROLD C. JEWETT. 

